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US 1,439,331 A · Inventors: ROBERT SCHOFIELD

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Listed from its USPTO record in Patent Yard's full-term archive. Its claims, description and drawings are in the USPTO PDF and on Google Patents, and the Claude kit works from them.

Why it's free to use

  • Granted December 19, 1922. A patent granted before 1976 lasted at most 17 years from grant, so its term ended by December 19, 1939.
  • We check US rights only. Old patents can still inspire new ones: improvements may be patentable.
FiledJune 27, 1922
GrantedDecember 19, 1922
Term endedDecember 19, 1939
Application number—
Classification (CPC)D02H3/00
Length4 pages

Timeline

Timeline From USPTO dates

192319251927192919311933193519371939Application filedJune 27, 1922Patent grantedDec 19, 1922Term endedDec 19, 1939

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